Process for breaking petroleum emulsions



Patented June 8, 1937 UNITED STATES PROCESS FOR BREAKING PETROLEUMEMULSIONS Melvin De Groote, St. Louis, Mo., assignor to The Tret-O-LiteCompany, Webster Groves, Mo., a

corporation of Missouri No Drawing. Application February 15, 1937,Serial No. 125,831

9 Claims.

This invention relates to the treatment of emulsions of mineral oil andwater, such as petroleum emulsions, for the purpose of separating theoil from the water.

Petroleum emulsions are of the water-in-oil type, and comprise finedroplets of naturallyoccurring waters or brines, dispersed in a more orless permanent state throughout the oil which constitutes the continuousphase of the emulsion. They are obtained from producing wells and fromthe bottom of oil storage tanks, and are commonly referred to as "cutoil, "roily oil, emulsified oil and bottom settlings.

The object of my invention is to provide a novel and inexpensive processfor separating emulsions of the character referred to into theircomponent parts of oil and water or brine.

Briefly described, my process consists in subjecting a petroleumemulsion of the water-in-oil type to the action ofa treating agent ordemulsifying agent of the kind hereinafter described, thereby causingthe emulsion to break down and separate into its component parts of oiland water or brine, when the emulsion is permitted toremain inaquiescent state after treatment, or is subjected to other equivalentseparatory procedures.

The treating agent or demulsifying agent contemplated by my processconsists of or comprises an alkylated naphthalene sulfonic acid in theform of a polyamine salt of the kind in which at least one alkyl groupsubstituted in the naphthalene nucleus contains not less than threecarbon atoms and not more than 10 carbon atoms, and the salt-formingamine is characterized by being of the type formula:

NH2.C2H4. (CzHaNH) aNHa where m is a whole number less than 20.

Amines of the kind described are obtained in various manners, andparticularly by the interaction of ethylene dichloride with ammonia,followed by liberation of' the free amine by treatment with caustic sodaor the like.

Commercial demulsifying agents employed for breaking or resolving oilfield emulsions include, among other substances, substituted polycyclicaromatic sulfonic acids or their salts. The type which finds mostfrequent application is obtained by introducing one, two or more alkylgroups into a naphthalene residue and then producing the sulfonic acids;or else, by the equivalent procedure of 'alkylating the sulfonic acids.Due to the corrosiveness of the sulfonic acid, it is the usual practiceto employ the reagent in the form of a salt, such as ammonium salt,potassium salt, sodium salt, etc.

I have found that if alkylated polycyclic aromatic sulfonic acids of thekind previously described are neutralized by means of triethylenetet'ramine, tetraethylene pentamine, pentaethylene hexamine, orhomolcgues or isologues of the same, one obtains a treating agent ordemulsifying agent of unusual effectiveness.

There does not appear to be any suitable explanation of this unusualsuperiority, and similarly, there does not seem to be any basis by whichone could anticipate or foresee this unusual efiectiveness. Apparently,this marked improvement is not directly related to oil or watersolubility, insofar that similar neutralization with other amines mayyield compounds which have a greater solubility in oily materials or inwater, and yet are not nearly as suitable and not nearly as effective intheir demulsifying action.

Apparently, there is some unlooked-for cooperation or chemical orphysico-chemical relationship between the polyamine residue of the kindpreviously described and the sulfo-aromatic polycyclic residue. Theneutralization of other con ventional acidic demulsifying reagents withthe amine of the kind previously described does not seem to produce anymarked improvement over the corresponding sodium or ammonium salts, andin many cases, yields an inferior product, thus indicating thatapparently the increased value does not reside in an additive effect,due to the amine residue of the kind previously described. If oneneutralizes other sulfonic acids, which are known to be effectivedemulsifying agents, such as petroleum sulfonic acids of the mahoganyacid type, with an amine of the kind previously described, one does notobtain a more effective demulsifying agent, and indeed, one is morelikely to obtain a demulsifying agent which is less effective. Based onthe results of actual tests obtained in a variety of emulsified crudesoccurring in a number of the major oil fields of the United States, theconclusion one must inevitably reach is, that the result obtained byuniting the two residues, i. e., the polyamine residue of the kindpreviously described and the described sulfo-aromatic polycyclic residuein a single molecule, results in an unlocked-for, unique quality, whichcould not be foreseen by the present knowledge of the art, and whichproduces a demulsifying agent that is particularly efiective for a largenumber of emulsified crude oils.

Alkylated naphthalene sulfonic acids are produced commercially, and thesalts are used for a variety of purposes. They are generally producedfrom naphthalene, because there does not appear to be any advantage inthe use of a naphthalene derivative, such as chlornaphthalene, alpha andbeta naphthol, etc. In other words, one could introduce the sulfonicacid residue and the alkyl residues into a substituted naphthalene, suchas chlor-naphthalene, etc., just as readily perhaps as in the case ofnaphthalene. Such simple derivatives, of course, are the chemicalequivalent of naphthalene in the manufacture of such sulfonic acids asare employed in the manufacture of the present reagent. It is understoodthat the word naphthalene is hereinafter employed to include thesederivatives.

The general process of manufacturing the demuisifying agent contemplatedby my process, consists in converting the naphthalene into either thealpha or beta naphthalene sulfonic acid, or a mixture of both, or insome instances, into a dior even a tri-sulfonic acid, or a mixture ofall the various types. In most instances there is no advantage inintroducing more than one sulfonic acid group. In many instances it isunnecessary to use particular care to prepare either only the alphasulfonic acid, or either only the beta sulfonic acid, because a mixturein which either one or the other predominates, or a mixture in which thealpha and beta sulfonic acids are present, is Just as satisfactory asone sulfonic acid completely freed from the other type.

The alcohols employed, such as propyl alcohols, butyl alcohols, amylalcohols, hexyl alcohols, decyl alcohols, etc. are converted into theacid sulfate,.such as propyl hydrogen sulfate, etc. The naphthalenesulfonic acid and the alkyl hydrogen sulfate are combined in proportionsso that one, two, three, or even four alkyl groups are introduced intothe polycyclic aromatic residue. This condensation reaction is generallycarried out in the presence of an excess of sulfuric acid. In someinstances, the various reactions, such as sulfonation, sulfation,condensation, etc. are carried out simultaneously. Generally speaking,the di-alkylated and tri-alkylated material appear to yield the mostdesirable type of reagent. The presence of some mono-alkylated material,or some tetra-alkylated material is not objectionable, and may even bedesirable.

It is obvious, of course, that the alkylated groups introduced might bederived from oieiines, such as butylene, propylene, amylene, etc.,insofar that such oleilnes react directly with sulfuric acid, to producethe alkyl hydrogen sulfates.

5 Of course, in addition to introducing such alkyl propyl alcohol.

residues of the kind described into the polycyclic aromatic nucleus, onecould also introduce an alkyl residue from some other alcohol, as, forexample, an alkylated group derived from ethyl or methyl alcohol, or onemight introduce a group derived from various alcohols such as aryl,aralkyl, cyclic, hydro-aromatic alcohols, etc., but regardless ofwhether or not one introduces such other residues, it is necessary thatat least one alkyl residue of the kind described, i. e., having at leastthree carbon atoms and not more than ten carbon atoms, be introducedinto the naphthalene ring. Such compounds having ome other substituentpresent, such as a methyl substituent, might be considered as beingderived from methyl naphthalene instead of naphthalene, and thus, wouldfall within the class of chemical types or equivalents previously noted.It is immaterial as to the particular alcohol employed, or theparticular isomeric form of the alcohol employed, although generallyspeaking, it is most desirable to use the one lowest in cost. It isimmaterial whether one uses normal propyl alcohol, or iso- It isimmaterial whether one uses a normal butyl or isobutyl alcohol. It isimmaterial whether the alcohol is a primary alcohol, or a secondaryalcohol, or a tertiary alcoagent employed in the present process. Forinstance, although the sulfonic group may be introduced into either thealpha or beta position, or a mixture of both, it is manifest that thealkyl group or groups can be introduced into various positions in regardto the position of the sulfonic acid group. Apparently, as far as I amaware, one isomeric form is as effective as the other. Reference to thecompounds is not intended to indicate any particular isomer, unless thetext clearly indicates some specific position.

Insofar that the most readily available alcohols, from the standpoint ofcost, are isopropyl alcohol, normal butyl alcohol, isobutyl alcohol, andamyl alcohol, it is my preference to produce my reagent from thesealcohols, and in some instances, it is desirable to introduce differentalkyl groups, such as a propyl group and butyl group, into the samesulfo-naphthalene residue.

In the actual manufacture of alkylated naphthalene sulfonic acids, thecompletion of the desired chemical reactions is followed by a washingprocess which removes the excess of sulfuric acid or other sulfonation,sulfation, or condensation reagent employed. The acidic mass thusobtained is neutralized with an amine product of the kind previouslydescribed in the same manner that sodium or potassium or ammoniumhydroxides might usually be employed. The final product, if itrepresents a pasty or semi-solid or a solid mass, is rendered suitablefor industrial use by the addition of a solvent, such as water, analcohol, a coal tar solvent, at petroleum hydrocarbon solvent, or in anysimilar manner.

The demulsifying agent that I prefer to use in practicing my process isobtained by a reaction in which three moles of propyl alcohol arereacted with one mole of naphthalene by the customary sulfonation,sulfonation and condensation reactions. The resulting mixture consistslargely of di-propyl naphthalene sulfonic acids and tripropylnaphthalene sulfonic acids, with possibly small amounts of mono-propylsulfonic acids and tetra-propyl sulfonic acids, and perhaps somedi-sulionic a ids present. Generally speaking, it is easier to conductthe reaction so that the bulk of the sulfonic acid represents the betatype, although the alpha type ma be roduced, if desired. The product isneutralized with tetraethylene pentamine, and is diluted with one ormore solvents, so as to reduce its viscosity to that of ordinary castoroil, or slightly greater. The solvent which I preferably employ is amixture of two or more of the following: water, denatured alcohol,kerosene, or tar acid oil.

Among the reagents which are particularly effective are the salts of thepolyamines of the kind previously described, of the following alkylatednaphthalene sulfonic acids, i. e., mono-isopropyl naphthalene sulfonicacids, di-isopropyi naphthalene sulfonic acids, tri-isopropylnaphthalene sulfonic acids, mono-normal butyl naphthalene sulfonicacids, di-normal butyl naphthalene sulfonic acids, mono-isobutylnaphthalene sulfonic acids, di-isobutyl naphthalene sulfonic acids,mono-amyl naphthalene sulfonic. acids, diamyl naphthalene sulfonicacids. tri-hex;, naphthalene sulfonic acids, mono-octyl naphthalenesulfonic acids, di-octyl naphthalene sulfon c acids, mono-decylnaphthalene sulfonic acids, dldecyl naphthalene sulfonic acids,mono-isopropyl-di-normal butyl naphthalene sulfonic acids,di-isopropyl-mono-amyl naphthalene smionic acids,mono-isopropyl-mono-hexyl r thalene sulfonic acids, etc.

In such instances where there is present more than one sulfonic acidgroup, as in the formation of di-sulfonic acids, or tri-sulfonic acids,if desired, all the sulfonic acid hydrogens may be neutralized with anamine of the kind previously described, or, if desired, all the sulfonicacid hydrogensmay be neutralized with an amine of the kind previouslydescribed, and the other sulfonic acid hydrogen atom or atoms may beneutralized with some other suitabe base, such as sodium hydroxide,potassium hydroxide, ammonium hydroxide, etc.

Salts of the polyamines of the kind previously described, such as thehydrochloride, may react by double decomposition with alkali sulfonatesin a suitable medium to produce the sulfonate of the amine of the kindpreviously described.

Conventional demulsifying agents employed in the treatment of oil fieldemulsions are used as such, or after dilution with any suitable solvent,such as water; petroleum hydrocarbons, such as gasoline, kerosene, stoveoil; a coal tar product, such as benzene, toluene, xylene, tar acid oil,cresol, anthracene .oil, etc. Alcohols, particularly aliphatic alcohols,such as methyl alcohol, ethyl alcohol, denatured alcohol, propylalcohols, butyl alcohols, hexyl alcohols, octyl alcohols, etc., may beemployed as diluents. Miscellaneous solvents, such as pine oil,'carbontetrachloride, sulfur dioxide extract obtained in the refining ofpetroleum, etc., may be employed as diluents. Similarly, the material ormaterials employed as the demulsifying agent of my process may beadmixed with one or more of the solvents customarily used in connectionwith conventional demulsifying agents. Moreover, said material ormaterials may be used alone or in admixture with other suitable wellknown classes of demulsifying agents, such as demulsifying agents of themodified fatty acid type, the petroleum sulfonate type, the alkylatedsulfo-aromatic type, in which the sulfonic hydrogen is neutralized bythe use of some base other than an amine of the kind previouslydescribed, or the like.

It is obvious that polyamines analogous to triethylene tetramine ortetraethylene pentamine, may be obtained by reactionsinvolving alkylenedichlorides other than ethylene dichloride. For instance, propylenedichloride. butylene dichloride, and amylene dichloride, can be treatedwith ammonia in a similar fashion so as to yield polyamines similar tothose described above. For this reason, the type of amine which may beemployed may be represented more broadly by the following type formula:

in which n represents the numeral 2, 3, 4, or 5, and a: is a wholenumber less than 20.

It is well known that conventional demulsifying agents may be used in awater-soluble form, or in an oil-soluble form, or in a form exhibitingboth oil and water solubility. Sometimes they may be used in a formwhich exhibits relatively as limited water solubility and relativelylimited oil solubility. However, since such reagents are sometimes usedin a ratio of l to 10,000 or 1 to 20,000, or even 1 to 30,000, such anapparent insolubility in oil and water is not significant, be-

70 cause said reagents undoubtedly have solubility 75 the reagent ordemulsifying agent contemplated in my process is based upon its abilityto treat certain emulsions more advantageously and at a somewhat lowercost than is possible with other available demulsifiers, or conventionalmixtures thereof. It is believed that the particular demulsifying agentor treating agent herein described will find comparatively limitedapplication, so far as the majority of oil field emulsions areconcerned; but I have found that such a demulsifying agent hascommercial value, as it will economically break or resolve oil fieldemulsions in a number of cases which cannot be treated as easily or atso low a cost with the demulsifying agents heretofore available.

In practicing my process, a treating agentor demulsifying agent of thekind above described is brought into contact with or caused to act uponthe emulsion to be treated in any of the various ways, or by any of thevarious apparatus now generally employed to resolve or break petroleumemulsions with a chemical reagent, or may be employed co-jointly incombination with other non-chemical processes intended to effectdemulsification.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a polyamine salt of an alkylatednaphthalene sulfonic acid in which at least one alkyl group substitutedin the naphthalene nucleus contains at least three carbon atoms and notmore than ten carbon atoms, the salt-forming amine being of the kindcharacterized by the type formula:

in which n. represents the numeral 2, 3, 4 or 5, and :t' is a wholenumber less than 20.

2. A process for breaking petroleum emulsions of the water-in-oil type.which consists in subjecting the emulsion to the action of ademulsifying agent comprising a polyamine salt of an alkylatednaphthalene sulfonic acid in which at least one alkyl group substitutedin the naphthalene nucleus contains at least three carbon atoms and notmore than ten carbon atoms, the salt-forming amine being of the kindcharacterized by the type formula:

wherein :n is a whole number less than 20.

3. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifylng agent comprising a polyamine salt of an amylatednaphthalene sulfonic acid, the saltforming amine being of the kindcharacterized by the type formula:

wherein a: is a whole number less than 20.

4. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a polyamine salt of a butylatednaphthalene sulfonic acid, the saltforming amine being of the kindcharacterized by the type formula:

NHz-CaI-h. (C2H4.NH) z-NH:

wherein a: is a whole number less than 20.

5. A process for breaking petroleum emulsions of the water -in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a polyamine salt of a propylatednaphthalene sulfonic acid, the saltforming amine being of the kindcharacterized by the type formula:

wherein a: is a whole number less than 20.

7. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a tetraethylene pentamine salt ofpropylated naphthalene mono-sulfonic acid.

8. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a tetraethylene pentamine salt ofpropylated naphthalene mono-sulfonic acid admixed with a suitablesolvent.

9. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsiiying agent obtained by converting naphthalene into themono-sulfonic acid, converting a propyl alcohol into the acid sulfate,combining said materials in molecular proportions in presence ofsulfuric acid as a condensing agent, followed by the conventionalwashing process and separation of the aqueous waste acid, andneutralization of the sulfonic acid, by means of tetraethylenepentamine, followed by addition of a suitable solvent.

MELVIN DE GROOTE.

